1. Field of the Invention
The present invention relates to a hatch cover and especially to a hatch cover for effectively closing and fluid sealing a hatch opening in a ship and analagous vessels.
2. Description of the Prior Art
The present invention is an improvement of my prior art hatch cover disclosed in U.S. Pat. No. 4,020,778 issued May 3, 1977.
As noted in the aforementioned patent, my previously patented hatch cover overcomes many of the drawbacks of other prior art hatch covers by providing a hatch cover with the capability of forming a water-tight seal after repeated closures, which is free of jamming and other malfunctions despite long exposure to salt water, which is mechanically simple and not dependent upon close tolerances between unnecessarily complex and numerous moving parts, and which eliminates the problem of lost or misplaced latch-actuating handles.
However, in my prior art hatch cover it is extremely difficult, if not impossible, to determine from visual inspection whether or not the hatch cover is securely fastened in place. Instead, time consuming checking and, in many cases, actual manipulation of the latching mechanism is required before it can be verified that the cover is latched. These difficulties associated with determining latched and unlatched conditions of a hatch cover are also common with other prior art hatch covers as well.
In addition, pressure can build up on one side of hatch covers used to seal cargo holds of barges and like vessels. When hatch covers used in these applications are opened, these pressure buildups are suddenly released and can move the covers abruptly, much to the surprise of the operator.
In view of the foregoing, there is a need for an improved hatch cover in which the latched condition thereof can quickly and easily be determined from visual inspection from a remote location. Furthermore, there is a need for such a hatch cover which eliminates the problems caused by a sudden pressure release, when opened, while at the same time providing a water-tight seal of the hatch opening when closed.